The present disclosure relates to microphone modeling and microphone sound-isolation baffles typically used for vocal and musical instrument recordings.
Historically, professional or commercial music and voice recordings typically have taken place in recording studios, concert halls, or sound stages. Recording studios, concert halls, and sound stages have generally provided controlled environments, with acoustics optimized for creating pleasing sound and for the control and abatement of noise. For example, a professional recording studio may be constructed so the studio environment is isolated from building, ventilation, and exterior noise. The recording studio is typically treated to control unwanted reflections and room resonances and otherwise balance the sound of the room. In addition, the recording studio is often divided into two rooms: A control room and a live room. The sound engineer operates the recording equipment in the control room. The musicians and vocalist perform in the live room. The live room acoustics are optimized for recording sound. The control room acoustics are optimized for critical listening.
In more recent times, with the explosion of low cost, high-quality, and computer-based audio recording equipment, many professional recordings are no longer made in the ideal professional studio environment described above. Many professional audio recordings for music, television production, or film production take place in less formal settings. These can often be in a home studio of the producer, musicians, or television or film scorers. These so-called project studios often have less than ideal acoustics. They rarely have sound isolation from the ventilation system, the outside environment, or the rest of the building. Often control room and studio functions take place in a single room so the musicians and vocalists are not isolated from equipment noise. In addition, these rooms are typically not acoustically balanced for recording. The combination of environmental noise and non-ideal acoustics creates challenges for creating professional high-quality audio recordings.
In recent years, microphone sound-isolation baffles were developed to address these challenges. Microphone sound-isolation baffles attempt to isolate the microphone and performer or the microphone and musical instrument from the acoustics of the room by partially surrounding the microphone. The microphone sound-isolation baffle can use sound absorption to control sound reflections. The microphone sound-isolation baffle can use a combination of sound absorption and reflection to reduce unwanted ambient noise. The microphone sound-isolation baffle typically does this while attempting to minimize added coloration (i.e. changing the audio frequency response) of the sound from the performer or musical instrument.
Traditionally, professional recording studios may invest in new high-quality studio condenser and ribbon microphones. For example, Neumann U87, Neumann U67, or the Sony C800G. They may also invest in classic microphones that are no longer being manufactured. For example, the Neumann U47, M50, or M49. The cost of these microphones is often beyond the budget of many project studios. Microphone modeling, also known as microphone emulation, was developed, to emulate the sound of these classic microphones, and bring this sound within the reach of project studios.
Microphone modeling works by recording audio, such as voice or musical instruments, and then applying a software model or some other post-processing of the emulated microphone to the recorded audio. A microphone used to record audio, such as a musical performance (i.e., voice and/or musical instruments), is called the source or reference microphone. The microphone modeled or emulated is called the target or destination microphone.
Some commercially available microphone modeling products allow the user to select a source microphone from a list of microphones and then choose a target microphone from another list of microphones. The source microphone list typically includes microphones commonly found in recording studios. The target microphone list typically includes sought after classic microphones such as those discussed in the preceding paragraph.
Other commercially available microphone modeling products require the user to record music using a reference microphone provided or recommended by the microphone modeling manufacturer. The reference microphone typically exhibits more tightly controlled frequency response and other characteristics so that the microphone modeler has a known starting point. Like in the first modeling scheme, the user would select from a list of target microphones to emulate. The reference microphone is typically a high-quality microphone and can have quality comparable to some of the classic target microphones. The reference microphone can generally produce more accurate and transparent sound reproduction than the general selection of source microphones in the first schedule.
Microphone modeling developers create the microphone models typically by recording each source microphones and each target microphones, one at a time, in a controlled studio environment or anechoic chamber using test signals. For example, the microphone modeling software manufacturer may record either a source microphone or target microphone using test signals, such as sine-sweep, noise, or impulses through the microphones so the frequency response and other characteristics of the microphone can be measured. Using the model of the source microphone, the microphone modeler, in effect, attempts to cancel the sonic contribution of the source microphone and then apply the modeled response of the target microphone to the signal.